In addition, yes, postal employees get seriously worried about losing their jobs when they make a mistake, especially where a guarantee by the Postal Service is concerned. They will lose their job if the infraction is deemed severe enough. It's common enough for postal employees to worry about their jobs: their employer, the federal government, has many strict regulations of their conduct. Also, the employee in question may not have been as well informed on the history of the book's release as you.
Perhaps I wasn't clear enough in saying that I was on a tangent. The CIA leak information may be solid, but the author detracts credibility for the sake of an interresting, but argueably incorrect lead in. Now then, what facts about the USPS am I woefully ignorant about? (btw - you woe way too easily if this is all it takes)